Metal weld fail.

[Halberds]

I sure did something wrong with this.

http://home.armourarchive.org/members/h ... erFail.JPG

The metal shattered like glass.
The pommel was rosset welded and while peening it snapped off.

Epic fail.
Now I have a dead rondell dagger.
It goes in the creek... as the hilt will snap also.
Well... maybe I can cut it off and make a spear head.

The metal was virgin automotive spring steel.
Temper "as is" from factory.
My welding seemed to have crystallize the steel and it became as brittle as glass.

I should of never welded it.

[hrolf]

heating spring steel anneals it...

i bet if you anneal it a bunch more, getting a spear won't be hard.

[Halberds]

Yes... if I heated it to red, the weld might of been OK.
However it would remove the spring temper in the blade.

This is the classic Catch 22.

Hal

PS: Getting the spear should be a piece of cake.
As I have a 14" Abrasive cut-off-saw.

The sad part was... I already made the sheath.

[Andrej Evtuh]

before welding will grind off a metal as rotined on a picture, then a weldable surface will be bigger. ideally it will be if you welding it by a stainless wire: stainless will give some elasticity. Welding is necessary the argon welding or to use gas argon. After welding it is necessary to warm up a welding area to the red color and give to get cold on air. Control the temperature of blade (a temperature must be not higher 100C). Right after welding and after the subsequent heating a blade can be simply inserted in a pipe with water. But! water must be not nearer 100 millimeter (4 inches) to the point of welding!

[Andrej Evtuh]

My armory is near of a factory on repair of tanks. This method told me specialist from there. They understand herein.

[Halberds]

Yes a weld chamfer is good for penetration.
My weld made the joint as brittle as glass.

[Andrej Evtuh]

Yes a weld chamfer is good for penetration.
My weld made the joint as brittle as glass.

hm, the problem is not in area of welding.... you weld steel with high maintenance of carbon. this steel can not be welded an ordinary method. in the place of welding high temperature deformations appear which result in instantaneous appearance of microseparation. As a result: fragile and unreliable connection...... Use the method described higher.

[Andrej Evtuh]

Oh, quite forgot..... Welding is needed the already warmed up metal A welding place must be dark blue (or brown) - red color.

[Signo]

I think that the weld cooled too fast, being carbon steel things can be pretty brittle if this is the case, then a bit of heat for some time should take care of it.
Weld it again, then relieve the internal stress with heat, but not anneal it. You can toss it away if you fail again.

[Andrej Evtuh]

... but not anneal it. You can toss it away if you fail again.

Excuse me, but Why?

[fungi forge]

Hi Hal

This is actualy a fairly easy fix. But if I'm looking at it right I think i see where it already had a small crack where it broke off. Its a different color where the crack was. If it was a crack it would have broken any how.

To fix it you can anneal just the end without hurting the blade. Put the blade in water with just the end out and heat it up with a torch. The water will stop the heat from traveling down to the blade. Then just weld and build the end back up regrind it and your set. And if your worried about it being brittel again anneal it again.

If your rondel is stainless. Ive seen it suck the heat from steel and that could of made it brittel also.

[Dierick]

I had a heat treated piece that I was tigging an untreated grill to with the same problem. Put a two inch snap in the helm skull. Wish I still had it laying around, the submerging in water while heating probably would have worked to anneal a small area to weld the grill to.

[Raeven]

Hal, why not just anneal the dagger and retemper it?

Weld it, then anneal it. Finish your hammer work on it, then harden and temper it again.

[Raeven]

Hi Hal

This is actualy a fairly easy fix. But if I'm looking at it right I think i see where it already had a small crack where it broke off. Its a different color where the crack was. If it was a crack it would have broken any how.

To fix it you can anneal just the end without hurting the blade. Put the blade in water with just the end out and heat it up with a torch. The water will stop the heat from traveling down to the blade. Then just weld and build the end back up regrind it and your set. And if your worried about it being brittel again anneal it again.

If your rondel is stainless. Ive seen it suck the heat from steel and that could of made it brittel also.

Hey, that's an awesome suggestion.

[Sean Powell]

There is a phenominon we see here occasionally with welding surgical cutting instruments (high carbon) to handles (low carbon). The weld are is >1800F. A few mm away the steel is only heated to to 1600. A few mm even farther 1400, then 1200 etc. At some point a tempered piece of spring steel will cross a 'blue brittle' zone and be more brittle then the cooler material to its left that wasn't heated as high and softer then the material to its right that was heated higher and effictivly annealed. This transition point has to occut SOMEPLACE or you will destroy the temper of the blade. The key is for it to occur in a non critical region (middle of the handle) rather then a critical one (where the tang has a stress riser)

I'd go with Fungi forges suggestion (pretty much what we do here in industry other then our quench medium is medical grade) and be certain you get the piece warm before welding. If it's inconvenient to weld with the blade actually submerged in water then a couple of heavily soaked rags will work fine.

Good Luck!
Sean

[losthelm]

hears a question would it work to just make the handle a bit shorter, and braze the pommel on?
The heat effected zone where the metal is most brittle would be put up higher in the the handle where there is more metal to take the stress. letting the hilt normalize may also help reduce the stress area.

What type of steel are you useing for filler?

[Maeryk]

Yes... if I heated it to red, the weld might of been OK.
However it would remove the spring temper in the blade.

This is the classic Catch 22.

Hal

PS: Getting the spear should be a piece of cake.
As I have a 14" Abrasive cut-off-saw.

The sad part was... I already made the sheath.

Could you pack the blade in something (like wet clay, or something) so ONLY the part you want annealed will heat to that level?

[Thomas Powers]

1 you don't need to anneal the tang! Just draw a deep temper on it.

2 when welding high carbon steel you need to preheat the metal to avoid "auto quenching" of the piece---heating up to the draw temper of the piece should be sufficient and will not mess up the temper of the blade---as it has already been to that temperature during tempering.

3: Tangs do NOT need to be hardened and in medieval times were often low carbon wrought iron anyway. Using modern monosteel techniques it is still a good idea to draw the temper on the tang *more* than the temper on the blade. The blade needs to hold an edge, the tang does not!

4 If the blade is too hard tempering in a kitchen oven is suggested followed by drawing the tang back a bit more with a propane torch.

5 this blade is still in play, you just need to draw temper on the tang and shorten the grip by a tad and re-hilt it.

Thomas

[J.G.Elmslie]

what strikes me more, is, why were you welding it in the first place, when a more appropriate method would've been to peirce the endcap, place it onto the tang, which I see is already profiled with a step so it'd seat cleanly, and then heat the tang end, and hot pein it over?

welding it strikes me as entirely excessive and inappropriate for the peice.

[Frederich Von Teufel]

As Thomas says, preheating the weld area can be important. Also important is the alloy of the steels being welded and the alloy of the fill rod. Type of sheild gas (or lack there of) can effect the weld. The final thing I would look to is how the weld is handled post-weld.

Any of those factors could create a problem at the transition point resulting in a failure.

Like Thomas, I don't think this piece deserves to be trashed, you simply may need to grind off the previous weld, check your specs, reweld and do a differential temper on the tang/rondel area.


Frederich

[Halberds]

Thanks for the help guys, I will have to revisit this project then.
Yes a little shorter handle sound good.

What happens when one welds a large hardened ball bearing to a shank like on a ball stake?
I have only used ductile iron balls and not a problem.

Hal

[AwP]

Hal, why not just anneal the dagger and retemper it?

Weld it, then anneal it. Finish your hammer work on it, then harden and temper it again.

I think this is the best way to go.

What happens when one welds a large hardened ball bearing to a shank like on a ball stake?
I have only used ductile iron balls and not a problem.

Hal

You need to preheat the ball, which will ruin the original HT, though depending on the alloy you could just re-HT it.

[sha-ul]

1 you don't need to anneal the tang! Just draw a deep temper on it.

2 when welding high carbon steel you need to preheat the metal to avoid "auto quenching" of the piece---heating up to the draw temper of the piece should be sufficient and will not mess up the temper of the blade---as it has already been to that temperature during tempering.

3: Tangs do NOT need to be hardened and in medieval times were often low carbon wrought iron anyway. Using modern monosteel techniques it is still a good idea to draw the temper on the tang *more* than the temper on the blade. The blade needs to hold an edge, the tang does not!

4 If the blade is too hard tempering in a kitchen oven is suggested followed by drawing the tang back a bit more with a propane torch.

5 this blade is still in play, you just need to draw temper on the tang and shorten the grip by a tad and re-hilt it.

Thomas

Thomas, how would one go about draw tempering this piece?

Hal, was this an old file?

[Halberds]

No, it was virgin automotive leaf spring A.I.S.I. grade 5160H.

As to why I did not just peen it.
I was taking a shortcut. [d'oh]

[The Iron Dwarf]

when welding hardened balls to mild steel I find the small ones are no problem if I turn the power up and do them quickly with either mig or stick.
if I weld part of it and wait a few seconds before doing the rest it can crack.
over 60mm balls ( 2 3/8" ) and I have to pre heat them as well as welding them fast

[Thomas Powers]

Drawing temper is heating the metal up to a temperature *usually* between 325 to 600 degF so some ranges can be done with a kitchen oven. But of course this draws temper on the entire piece.

For a differential temper you can use a torch---even a simple plumber's torch; or tempering tongs, or even wrapping the blade in sopping wet rags and sticking the tang in a charcoal fire! The important thing is to NOT bring it up to hardening temp again---we want to be almost 1000 deg F *cooler*!

(Unusual alloys can have unusual draw temps---blacksmiths love using alloys that have draw temps about *glowing* for tools that will spend a lot of time buried in red hot metal...)

Blacksmiths often judge tempering temps by the colour of the metal---oxide thickness not *glowing* colours. Many knife blades get tempered to golden or dark straw while tangs will be blue or even gunmetal grey.

Thomas

[Halberds]

Interesting... The blade does not bent at the tang?

[Jurgen]

Thanks for the help guys, I will have to revisit this project then.
Yes a little shorter handle sound good.

What happens when one welds a large hardened ball bearing to a shank like on a ball stake?
I have only used ductile iron balls and not a problem.

Hal

I've just tossed them in the oven or gas grill to get them up to around 500 degrees, then MIG welded them. None of them have ever failed, and it didn't seem to affect the hardness of the ball enough that I noticed.

Jurgen

[AwP]

Interesting... The blade does not bent at the tang?

Not usually, maybe in an extreme situation like if you were using a hammer to pound it through armor. But in that case which is worse, bending or snapping?

[Ironbadger]

Hmm...

When I was making knives, I annealed tangs to prevent breakage.
Not much.
Just enough to make them soft enough to cut easily with a file.

I attached guards and sometimes pommels with silver solder.
(Pommels were usually also pinned, threaded or peened.)

Theres a lot of ways to do it, actually, but welding one is new to me.

Not saying other knifemakers don't do it, just that I never saw it done before.
I usually used brass furniture in any case, so welding wasn't an option.

-Badger-

[Ckanite]

I've welded a tang once for a welded sword, just a wall hanger. I'll never do it again, I always make them soft enough to peen. I've never tried the pin method... maybe I should give that a shot...

[Halberds]

Could you elaborate on the Pin Method?

Is it what I think it is?
Drill and pin the cross guard?

[Ironbadger]

For pinning, I did this on pommels.

A method I sometimes used was to drill or cut a slot into the pommel, make a nice, wide tang that fit inside and drill a hole through the flat side of the pommel piece.

A very tightly fitted pin was tapped in, and both sides lightly peened down, then the entire surface simply ground/sanded smooth.

If I wanted it to absolutely never move at all, I would dribble flux down into the slot hole, then heat and use plumber's solder to fill the entire cavity.
(Just warm it from below slowly with a propane torch while its gripped in either a vice, or with a vicegrips held in a vice, until the solder melts and sinks into the hole- adding more until it fills up.)
Must be held level and vertical for this to work.

This resulted in a big, beefy pommel tang that would absolutely never break off, was completely solid, and took very little effort.

I did not always trust threaded tangs.


Its suitable only when the piece of metal used for the pommel is thick and broad- something like 3/4inch thick by 1 1/4 or wider so theres something to work with, rather than a large disk or a simple cap.
This trick also works for large ball or other shapes.

Obviously, the grip added later is a sandwich enclosing the tang.

I never did this with guards- those I just silver soldered for a secure fit.

-Badger-

Could you elaborate on the Pin Method?

Is it what I think it is?
Drill and pin the cross guard?